Coreless winding apparatus

ABSTRACT

Disclosed is an apparatus for forming coreless paper rolls. The invention is an inflatable mandrel that can take on an increased diameter while a paper web is being wound around its outer surface. The mandrel can then be deflated to decrease the diameter sufficiently to allow for the removal of the paper roll.

RELATED APPLICATION DATA

This application is a continuation-in-part of co-pending application Ser. No. 60/737,814 filed on Nov. 17, 2005 and entitled Coreless Mandrel Operation, the contents of this application are fully incorporated herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a coreless winding apparatus. More specifically, the present invention relates to a rewinding apparatus that employs an expansible mandrel whereby coreless rolls of paper can be created.

2. Description of the Background Art

Devices for use in constructing coreless rolls are known in the art. For instance, U.S. Pat. No. 4,695,005 to Gietman discloses a winder for making coreless rolls of pliable sheet material, such as plastic, cloth, or paper. The paper is initially rolled about a pair of rods and after a sufficient amount of material has been wound, the rods are collapsed towards one another. Thereafter, an air cylinder is activated to cause a push off plate to force the roll off the rods. The result is a coreless roll of material.

Similarly, U.S. Pat. No. 5,497,959 to Johnson discloses a coreless winding method. The leading edge of a sheet of paper, such as the type used for bathroom or kitchen toweling, is secured to a mandrel by way of suction delivered axially through the mandrel. Once a sufficient amount of material has been wound upon the mandrel, the resulting log is stripped from the mandrel.

U.S. Pat. No. 5,453,070 to Moody discloses a system for manufacturing a coreless roll of a paper product. A roll is initially formed upon a mandrel, after which a portion of the roll is pushed onto a support shaft by way of a pusher device. With a portion of the roll on the shaft, a saw blade is used to cut the roll to a desired width and form a roll segment. The individual roll segments are then removed from the shaft by a pusher element.

Finally, U.S. Pat. No. 1,977,668 to Dallas discloses a winding machine including a rotatable arbor. The cross section of the arbor can be expanded or reduced by way of a series of slides to assist in ejecting a wound roll. With the cross section of the arbor in its reduced configuration, an ejector collar is used to push the roll from the arbor.

Although each of the above referenced inventions achieves its individual objective, they all suffer from a common drawback. Namely, all of the referenced inventions require complex and especially designed machinery to create coreless rolls. The present invention overcomes this deficiency by allowing coreless rolls to be formed on existing rewinding machines without the need to purchase costly and complicated equipment.

SUMMARY OF THE INVENTION

It is therefore an objective of this invention to facilitate the manufacture of coreless paper rolls.

It is another objective of this invention to provide an expansible mandrel that can be used to construct coreless rolls.

It is also an objective of this invention to enable existing rewinders to construct coreless receipt rolls.

These and other objectives are achieved by a mandrel that includes an elongated rigid shaft with an outer cylindrical surfaces, first and second ends and an intermediate extent. The shaft includes a hollow interior, first and second threaded extents, and recesses formed within the outer cylindrical surface. First and second air ports are formed through the outer cylindrical surface of the shaft proximate the two threaded ends. The mandrel further includes a length of flexible tubing that is equal in length to the shaft. The tubing is fitted over top of the cylindrical surface of the rigid shaft. Lengths of thread are wound around the flexible tubing over the recesses to thereby create a seal between the tubing and shaft. A threaded end cap is secured within the first threaded extent of the rigid shaft. The cap includes an integral air valve for selectively delivering pressurized air into the hollow interior of the shaft. A threaded plug with a peripheral seal is threadably secured within the second threaded extent of the rigid shaft such that the peripheral seal forms a fluid tight barrier within the second end of the rigid shaft. A source of compressed air is supplied and is adapted to be delivered into the hollow interior of the rigid shaft via the air valve and through the air ports. The delivery of the compressed air causes annular spaces to be created between the recesses of the shaft and between the shaft and the tubing. The creation of the annular spaces, in turn, causes an increase in the outer diameter of the mandrel. The air valve functions to retain the compressed air within the mandrel during winding operations and further allows an operator to release the compressed air once winding operations are complete.

The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:

FIG. 1 is a prospective view of the rewinder used in conjunction with the present invention.

FIG. 2 is a detailed view of the slitters that are used on the rewinder of the present invention.

FIG. 3 is a detailed view of a mandrel that is used in supporting a paper roll.

FIG. 4 is a detailed view of the expansible mandrel of the present invention.

FIG. 5 is an end view of the mandrel of the present invention taken along line 5-5 of FIG. 4.

FIG. 6 is a detailed view of an inflated mandrel of the present invention.

FIG. 7 is a sectional view of the mandrel taken along line 7-7 of FIG. 5.

FIG. 8 is an exploded view of the mandrel of the present invention.

Similar reference characters refer to similar parts throughout the several views of the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention relates to an apparatus for forming coreless paper rolls. The invention is a mandrel construction that can be inflated with air to take on an increased diameter while a paper web is being wound around its outer surface. The mandrel can then be deflated to decrease the diameter sufficiently to allow for the removal of the paper roll. The result is a paper roll that does not need to be supported with a disposable core. The mandrel can be used on existing rewinders, such as the type described below.

Rewinder Apparatus

FIG. 1 illustrates a rewinder 10 that can be used in conjunction with the mandrel of the present invention. More specifically, the depicted rewinder is a surface winder sold by Dusenbery Worldwide. As is known in the art, such rewinders include a supply roll 20 from which a web of material 22 is unwound. Thereafter, web 22 is delivered over a number of transport rollers and a series of slitters 26 (note FIG. 2). Slitters 26 are spaced to cut web 22 into a number of smaller webs whereby rolls of a desired width can be constructed. After being cut, web 22 is rewound into a take-up roll 24.

FIG. 2 illustrates slitters 26 disposed at the lower portion of rewinder 10. The rewinder depicted has its slitters configured to form register receipt rolls. Rewinder 10 also includes a carousel 28 (note FIG. 3) that can accommodate a series of mandrels 32, each of which can accommodate a take up roll 24. The carousel 28 allows one mandrel to be unloaded while another mandrel supports as a take-up roll 24. Mandrels are secured upon the carousel 28 via opposing mandrel guides 34.

FIG. 3 is a detailed view illustrating one of the mandrels 32 after a suitable length of paper web 22 has been wound upon it. The mandrel 32 has just been released from carousel 28 and the individual rolls 24 a are ready to be removed. In the present invention, the cross section of mandrel 32 is reduced after being removed from carousel 28 such that the rolls can be easily removed. The exact operation of expansible mandrel 32 is described in greater detail hereinafter.

In conventional mandrels, web 22 is wound about both a mandrel and a series of cores (not illustrated) that are positioned on the mandrel. After winding is complete, the conventional mandrel is removed from carousel 28 and the mandrel is removed from the interior of the cores. The result is a series of individual rolls each supported by a disposable core.

Inflatable Mandrel

The present invention relates to a mandrel construction 40 that can be used with existing rewinders, such as the rewinder depicted in FIG. 1. Mandrel 40 of the present invention is specifically constructed to allow rolls of paper, such as register receipt rolls 24 a, to be formed without the need for plastic or fiber cores. This is achieved by providing inflatable mandrel 40, whereby the outside diameter of the mandrel can be increased via a working fluid during winding operations. Thereafter, once the desired amount of material 22 has been wound upon the mandrel, it can be deflated, thereby decreasing the outside diameter and allowing enough clearance to cleanly remove rolls 24 a from mandrel 40 without disturbing the inside of the wound rolls.

FIG. 4 is an illustration of mandrel 40 in its uninflated and unexpanded state, and FIG. 6 is a view of mandrel 40 in its inflated and expanded state. FIGS. 7 and 8 are cross-sectional and exploded views, respectively, of mandrel 40 and its associated components. These figures show the elongated rigid shaft 42 that forms the primary component of mandrel 40. Rigid shaft 42, which is preferably constructed from a hardened steel, is defined by an outer generally cylindrical surface 44, first and second ends (46 and 48, respectively), and an intermediate extent 52. The exact length of shaft 42 will depend upon the specific type of product being wound. Nonetheless, in the case of register receipt rolls, the preferred length is 53.5″ or greater. This length allows a number of standard register receipt rolls 24 a to be made upon a single mandrel 40. It is within the scope of the present invention to use shorter or longer shafts. For example, many winding operations call for the use of 2″ shafts. The mandrel of the present invention can be used in winding a variety of materials, such as plastic, foil and foil laminates.

As noted in FIG. 7, shaft 42 has a hollow interior 54 that can be sealed at both ends. In the preferred embodiment, first and second threaded extents (56 and 58, respectively) are sealed by an end cap 62 and end plug 64, respectively. In the depicted embodiment, first threaded extent 56 is located at the first end 46 of shaft 42, while the second threaded extent 58 is recessed inwardly of second end 48 of shaft 42. This recessed area 66 between the threaded end 58 and the end of the shaft 48 allows for the insertion of end plug 64. Nonetheless, it is within the scope of the present invention to employ a mandrel 40 without this recess; namely, to provide the second threaded extent 58 at the second end 48 of shaft 42.

With continuing reference to FIGS. 7 and 8, shaft 42 also includes circular recesses formed around outer surface 44 of shaft 42. In the preferred embodiment, first and second recesses (68 and 72, respectively) are located at the first end 46 and at the midpoint 52 of shaft 42. The exact function of these recesses is described more fully hereinafter. The shaft further includes air ports 74 formed through the outer wall. In the depicted embodiment; two air ports 74 are included proximate the threaded extents 56 and 58 of shaft 42. Air ports 74 permit compressed air to escape from hollow interior 54 of shaft 42 and, thereby, inflate mandrel 40.

The expandability of mandrel 40 is created by fitting a length of flexible tubing 76 over top of rigid shaft 42. The preferred tubing 76 is formed from polyvinylchloride (PVC). This PVC tubing can optionally be reinforced with fibers. A nylon braded PVC tubing can also be employed. Nonetheless, it has been discovered that a clear unreinforced PVC tubing is most beneficial in promoting a uniform expansion of mandrel 40. The use of other flexible plastic tubings is also within the scope of the present invention. Flexible tubing 76 preferably has a length that corresponds to the length of rigid shaft 42. A snug fit between tubing 76 and shaft 42 is necessary to ensure that the outside diameter of mandrel 40 is as concentric as possible in both the inflated and deflated state.

Thus, in one exemplary embodiment, the inside diameter of tubing 76 is approximately 0.5″ while the outside diameter of shaft 42 is approximately 0.545″. It has been found that this 0.045″ clearance creates a sufficiently snug fit to yield a uniform outer diameter in the inflated and deflated states. Yet, such a small clearance makes it difficult to fit tubing 76 over shaft 42. In order to overcome this, air under pressure is delivered to the interior of shaft 42 while tubing 76 is being fitted. Tubing 76 is first manually fitted over shaft 42 a sufficient distance to cover one of the two air ports 74. Thereafter, compressed air is delivered to the interior 54 of shaft 42 and out through the air ports 74. This serves to create an air cushion between shaft 42 and tubing 76 which, in turn, permits tubing 76 to be slid over the remaining length of shaft 42.

After tubing 76 is fitted over shaft 42, it is then sealed to shaft 42 via wound thread 78 and adhesives. In the preferred embodiment, a cloth type thread 78, such as sewing thread, is employed for this purpose. Thread 78 is wound around both tubing 76 and shaft 42 at locations corresponding to the two circular recesses (68 and 72) within shaft 42 to promote bonding between shaft 42 and tubing 76. Prior to the thread being wound, these areas are first covered with a layer of epoxy. Additional bonding is obtained by coating the thread in an adhesive, such as superglue, before winding it about the tubing. After these adhesives are applied, thread 78 is then wound around tubing 76 and shaft 42 over top of recesses 68 and 72. This winding is done under tension. It has been found that winding the thread 30 times over each recess is sufficient. The adhesives allow thread 78 to be secured to the outer surface of tubing 76 and ensures an airtight seal is formed between tubing 76 and shaft 42. Tension is applied during the winding step because it is critical that no other part of mandrel 40 is larger than the outside diameter of tube 76 in its uninflated state. By winding thread 78 over recesses 68 and 72 of shaft 42 under tension, thread 78 slightly compress tubing 76 so as not to create enlarged portions that would otherwise hinder removal of wound rolls 24 a after deflation. Winding thread 78 over the first recess 68 adjacent the first end 46 of shaft 42 creates an airtight seal that prevents the air from escaping from the end of mandrel 40 after inflation. The thread 78 secured over the centrally located recess 72 performs a slightly different function. Namely, this thread 78, which is applied in the same way as the thread 78 over the first recess 68, ensures that there is no unwanted warping or curvature of tubing 76 over the length of mandrel 40.

In order to keep the mandrel inflated end caps are threadably received into the ends of the mandrel. With reference now to FIG. 8, the first threaded end cap 56 is depicted. This end cap 56 includes male threads 82 that permit cap 56 to be releasably secured into the first female threaded extent 56 of rigid shaft 42. This engagement forms a pneumatic seal between the hollow interior 54 and the outside of shaft 42. End cap 62 further includes an integral air valve 84, which can be similar to the air valve found in a bicycle tire. Air valve 84 is axially aligned with end cap 62 and allows air to be selectively delivered under pressure to hollow interior 54 of shaft 42. More specifically, air valve 84 includes a valve stem 86 that is spring loaded, whereby air is admitted to the interior 54 of shaft 42 only when the external pressure is greater than the internal pressure. Valve 84 also permits air to be released from the interior 54 of shaft 42 by manually depressing valve stem 86. Although end cap 62 is described and depicted with a threaded interconnection, those skilled in the art will appreciate that other types of interconnections, such as a friction fit or interlocking tabs, will suffice. It is also within the scope of the present invention to provide end cap 62 that is integral with, yet smaller than, shaft 42.

FIG. 8 also discloses the threaded end plug 64 which is threadably secured within the opposite end 48 of shaft 42. Again, plug 64 includes a male threaded extent 88 that mates with the female threaded extent 58 of shaft 42 to form a pneumatic seal. As with end cap 62, other types of interconnections are within the scope of the present invention. Threaded plug 64 also includes one or more peripheral seals 92 that form an air barrier adjacent the recessed end 66 of shaft 42. The space between seals 92 and the body of plug 64 creates an additional recess that permits an additional amount of thread 78 to be wound about the surface of tubing 76 in a manner described in detail hereinabove. This additional thread forms a barrier to prevent air from escaping from the second end 48 of mandrel 40. As noted above, the recess created by plug 64 ensures that no enlarged areas interfere with the removal of wound rolls 24 a.

Once both the threaded plug 64 and end cap 62 are secure, and the mandrel 40 is otherwise assembled, air can be delivered under pressure to the interior 54 of shaft 42 by way of a supply of compressed air. In this regard, a length of tubing 94 is provided adjacent the winding apparatus, with one end of the tubing connected to the source of compressed air and the other end 96 adapted for selectively engaging air valve 84. Once compressed air is delivered through the air valve 84 to the interior 54 of the shaft 42, it then travels out through the two air ports 74 and inflates mandrel 40. More specifically, the compressed air fills annular areas bounded by the circular recesses (68 and 72), the outer surface of shaft 42 and the inner surface of tubing 76. In the preferred embodiment, air is delivered at 125 psi to achieve a desired degree of inflation.

In one particular embodiment, air delivered at 125 psi was sufficient to increase the outer diameter of the mandrel from 0.8″ to 0.84.″ These, however, are only representative dimensions. Nonetheless, for the purpose of forming register receipt rolls, mandrels with an expanded outside diameter of approximately 0.875″ are preferred. Nonetheless, mandrels with a significantly reduced outside diameter can also be made in accordance with the present invention. Additionally, although the preferred embodiment has been described with air as the working fluid, the present invention can also be used with hydraulic oil as the working fluid. In this embodiment, care should be taken to use tubing that is impermeable to oil.

The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention.

Now that the invention has been described, 

1. A mandrel for use within a winding apparatus having opposing mandrel guides, the mandrel permitting the production of coreless rolls and comprising: an elongated rigid shaft having a length of 53.5″ or greater, an outer cylindrical surface, first and second ends and an intermediate extent therebetween, the shaft including a hollow interior with first and second threaded extents, recesses formed within the outer cylindrical surface, first and second air ports formed through the outer cylindrical surface proximate the first and second threaded extents; a length of flexible tubing formed from polyvinylchloride, the tubing having a length that is equal to the length of the rigid shaft, the tubing fitted over top of the outer cylindrical surface of the rigid shaft, lengths of thread wound around the flexible tubing over the recesses to thereby form a seal between the flexible tubing and the rigid shaft; a threaded end cap threadably secured within the first threaded extent of the rigid shaft, the threaded end cap including an integral air valve for selectively delivering pressurized air into the hollow interior of the rigid shaft; a threaded plug with a peripheral seal threadably secured within the second threaded extent of the rigid shaft such that the peripheral seal forms a fluid tight barrier within the second end of the rigid shaft; a source of compressed air for delivery to the hollow interior of the rigid shaft via the air valve, and through the air ports, the delivery of compressed air causing annual spaces to be created between the recesses of the shaft and between the shaft and the tubing, the creation of the annular spaces in turn causing an increase in the outer diameter of the mandrel, the air valve functioning to retain the compressed air within the mandrel while the mandrel is mounted to the mandrel guides of the winding apparatus, the air valve further functioning to allow an operator to selectively release the compressed air from the mandrel after the mandrel is removed from the mandrel guides at the conclusion of winding operations.
 2. An expansible mandrel comprising: a shaft with first and second ends and a hollow interior and at least one air port formed along its length; a length of tubing secured over the shaft, the tubing being sealed to the first and second ends of the shaft; an air valve coupled to one end of the shaft; a source of compressed air for selective delivery into the hollow interior of the shaft and through the air port, whereby the tubing is inflated and the diameter of the mandrel is increased.
 3. The mandrel as described in claim 2 wherein the air valve is incorporated into an end cap that is threadably secured within an end of the shaft.
 4. The mandrel as described in claim 2 wherein the tubing is sealed to the shaft via wound thread and adhesive.
 5. The mandrel as described in claim 2 wherein the length of the mandrel is greater than 53.5″.
 6. The mandrel is described in claim 2 wherein the outer diameter of the mandrel in its expanded state is less than 0.875″.
 7. The mandrel as described in claim 2 wherein the tubing is a flexible polyvinylchloride tubing.
 8. A method of making coreless rolls, the method employing a mandrel adapted to be removably secured between the opposing mandrel guides of a winding apparatus, the mandrel having an inner rigid shaft with an air valve and an air port and having an outer flexible tubing that is secured over top of the shaft, the method comprising the following steps: supplying air under pressure into the shaft via the air valve, the pressurized air being expelled from the shaft via the air port and causing the outer flexible tubing to expand to an increased diameter, whereby the mandrel is in an inflated state; removing the supply of air under pressure, whereby the air valve is closed and the mandrel is maintained in an inflated state; securing the mandrel in the inflated state between the opposing mandrel guides of the winding apparatus; winding a sheet of material over the mandrel while it is in the inflated state; removing the mandrel from the opposing mandrel guides after a sufficient amount of material has been wound upon the mandrel; manually engaging the air valve to permit pressurized air to escape from the mandrel, whereby the flexible tubing contracts and the mandrel takes on a deflated state; sliding the wound material off of the mandrel while the mandrel is in the deflated state.
 9. The method as described in claim 8 wherein a number of separate register receipt rolls are formed upon the mandrel.
 10. The method as described in claim 8 wherein the user employs a tool to manually engage the air valve. 